I need some help with skyboxes

[Spirit]

TL;DR How can I put a ring of fog inside my skybox that hides the otherwise very much visible edges of the animated cloud layer?

 

So, I made a skybox, and I want a cloud layer in it. I loaded up Yavin2 (I want a similar skybox to that map's) and looked at the way the skybox is made. It seemed like the cloud layer was a brush, so I made it that way. I had some problems with it causing HOM effect, but I figured out that making the cloud brush a detail brush fixes that. However, the edge of the cloud layer is very clearly defined, at the walls of the skybox. On Yavin2 it's fixed by what appears to be a ring of fog, a tube with some sort of foggy texture that hides the upper edges of the skybox, and with it, creates a smooth transition for the cloud layer. So I tried that, I made a tube, and tried all sorts of fog textures on it, however, none of them appears in the game. Which texture should I use? Am I even trying to do this the right way? Google doesn't help.

[Lazarus]

A brush is kind of the wrong way, better use a layered texture in it with a tcMod scroll function.

 

The best way to achieve that is looking at the `hevil` sky

textures/skies/hevil
{
	q3map_lightimage	textures/colors/white
	qer_editorimage	textures/skies/sky
	q3map_surfacelight	800
	q3map_lightsubdivide	512
	sun 1 1 1 400 300 50
	surfaceparm	sky
	surfaceparm	noimpact
	surfaceparm	nomarks
	notc
	q3map_nolightmap
	skyParms	textures/skies/hevil 128 -
    {
        map textures/skies/cloudlayer2
        blendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
        tcMod scroll 0 0.00225
        tcMod scale 4 4
    }
}

And the cloud layer

textures/skies/cloudlayer2
{
	surfaceparm	noimpact
	surfaceparm	nomarks
	notc
	q3map_nolightmap
    {
        map textures/skies/cloudlayer2
        blendFunc GL_DST_ALPHA GL_SRC_COLOR
        tcMod scroll 0.005 0
    }
    {
        map textures/skies/cloudlayer3
        blendFunc GL_SRC_ALPHA GL_SRC_COLOR
        tcMod scroll 0.01 0
    }
}

[Spirit]

 

A brush is kind of the wrong way, better use a layered texture in it with a tcMod scroll function.

 

The best way to achieve that is looking at the `hevil` sky

textures/skies/hevil
{
	q3map_lightimage	textures/colors/white
	qer_editorimage	textures/skies/sky
	q3map_surfacelight	800
	q3map_lightsubdivide	512
	sun 1 1 1 400 300 50
	surfaceparm	sky
	surfaceparm	noimpact
	surfaceparm	nomarks
	notc
	q3map_nolightmap
	skyParms	textures/skies/hevil 128 -
    {
        map textures/skies/cloudlayer2
        blendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
        tcMod scroll 0 0.00225
        tcMod scale 4 4
    }
}

And the cloud layer

textures/skies/cloudlayer2
{
	surfaceparm	noimpact
	surfaceparm	nomarks
	notc
	q3map_nolightmap
    {
        map textures/skies/cloudlayer2
        blendFunc GL_DST_ALPHA GL_SRC_COLOR
        tcMod scroll 0.005 0
    }
    {
        map textures/skies/cloudlayer3
        blendFunc GL_SRC_ALPHA GL_SRC_COLOR
        tcMod scroll 0.01 0
    }
}

Using a layered texture is not good for me, for multiple reasons. All I want is the texture used in Yavin2's skybox, the texture on the vertical tube of fog that hides the edges of the skybox from the player. I tried finding it, but none of the fog textures seem to work so it must be something else. I thought that people with more mapping experience would know it.

[kwenga]

textures/common/gradient2

[Spirit]

textures/common/gradient2

Thanks!